(a) Field of the Invention
The present invention relates to a method and a system for displaying efficiency of regenerative braking for an environmentally-friendly vehicle, and more particularly, to a method and a system for displaying efficiency of regenerative braking for an environmentally-friendly vehicle to better educate drivers in regards to their braking habits and hopefully teach them how to improve the fuel efficiency of the vehicle through adjustment of their braking habits while improving the quality of a vehicle by displaying an efficiency of the amount of regenerative braking in comparison to a total amount of braking on a cluster while the driver is braking.
(b) Description of the Related Art
As is well known, an environmentally-friendly vehicle generally includes a fuel cell vehicle, an electric vehicle, a plug-in electric vehicle, and a hybrid vehicle, and typically includes therein a motor for generating at least a portion of the driving force.
A hybrid vehicle, which is an example of the environmentally-friendly vehicle uses an internal combustion engine and power of a battery together. That is, the hybrid vehicle efficiently combines and uses power from the internal combustion engine and power of the motor in combination to provide both a sufficient amount of power and fuel efficiency in one vehicle.
The hybrid vehicle includes, for example, as illustrated in FIG. 1, an engine 10, a motor 20, an engine clutch 30 for controlling power between the engine 10 and the motor 20, a transmission 40, a differential gear apparatus 50, a battery 60, an integrated starter-generator 70 for starting the engine 10 or generating electricity by output of the engine 10, and wheels 80.
Further, the hybrid vehicle may include a hybrid control unit (HCU) 200 for controlling an entire operation of the hybrid vehicle, an engine control unit (ECU) 110 for controlling an operation of the engine 10, a motor control unit (MCU) 120 for controlling an operation of the motor 20; a transmission control unit (TCU) 140 for controlling an operation of the transmission 40; and a battery control unit (BCU) 160 for controlling and managing the battery 60.
In some systems, the battery control unit 160 is sometimes referred to in the art as a battery management system (BMS). The integrated starter-generator 70 may be called an integrated starter & generator (ISG), or a hybrid starter & generator (HSG).
The hybrid vehicle may be driven in a driving mode, such as an electric vehicle (EV) mode, which is a true electric vehicle mode using only power from the motor 20, a hybrid electric vehicle (HEV) mode, which uses rotational force from the engine 10 as main power, and uses rotational force from the motor 20 as auxiliary power, and a regenerative braking (RB) mode for collecting braking and inertial energy while braking or inertia of the vehicle through electric generation produced the motor 20 to charge the battery 60.
The hybrid vehicle may display regenerative braking state in a cluster as illustrated in FIG. 2 in order to notify the user of the regenerative braking state while performing regenerative braking of the hybrid vehicle.
A driver may identify a conversion of braking energy to electrical energy according to regenerative braking by viewing the display of the cluster as illustrated in FIG. 2.
Regarding the electrical energy converted according to the regenerative braking, as is well known to those skilled in the art, a larger electrical energy is charged in a battery due to gradual braking in comparison to sudden braking, because the braking ratio to oil pressure is increased during sudden braking requiring a larger amount of braking power. As a result, the ratio of electrical energy obtainable through regenerative braking is decreases relatively.
For example, the relationship between regenerative braking energy converted to electrical energy during sudden braking and gradual braking is represented by graphs shown in FIGS. 3A-B. In particular, FIG. 3A illustrates the relationship between regenerative braking energy converted to electrical energy during gradual braking and FIG. 3B illustrates the relationship between regenerative braking energy converted to electrical energy during sudden braking. However, in an exemplary embodiment of the related art illustrated in FIG. 2, the amount of converted electrical energy is displayed via a thickness of a line connected to the battery, and the thickness of the line is displayed to be larger during sudden braking in the related art. As a result, a driver and/or a user may misinterpret that that thicker line does not correlate to a larger amount of converted electrical energy. In fact, it is just the opposite.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.